Interlocking Corner Joint

ABSTRACT

A method of constructing an interlocking corner joint by combining fixed or variable sized interlocking fingers from at least two sides, full or partial feed though dowel pegs or other geometrically shaped pegs, finishing nails, pins or screws and glue or epoxy at the interface of the interlocking fingers and pegs and pins. The resulting interlocking corner joint is much stronger than a standard dovetail joint or box finger joint due to the increased surface area created by the holes, pegs and pins. Due to the interlocking fingers, holes, pegs and pins, the interlocking corner joint will not pull apart in any one dimension x,y,z in the event that the glue joint fails.

FIELD OF THE INVENTION

The present invention pertains generally to furniture manufacturing and specifically but is not limited to the making of drawer box joints.

BACKGROUND OF THE INVENTION

Drawer box joints are generally made several ways from wood of varying species or composite woods and vary from manufacturer to manufacturer. Drawer box joints generally are made from finger box joints, dovetail joints, lap joints, tongue and groove joints and other similar joints.

Drawer box joints are typically fastened together with some type of wood glue or epoxy and where the glue or epoxy is applied directly at the interface between the pieces of wood that overlap. In some cases mechanical plates are applied in addition to the glue joints. This added mechanical fastener provides additional strength to the joint and makes the joint less susceptible to mechanical stress over time. Drawer box joints with mechanical plates are much more expensive than drawers box joints without mechanical plates.

Most drawer box joints without mechanical plates are susceptible to failure in at least one or more of three possible x,y,z dimensions due to mechanical stress over time. The strength of the joint depends on the type of glue or epoxy used and the type of joint chosen. The strongest drawer box joint, a dovetail joint, may pull apart in one of the three x,y,z dimensions upon failure of the glue joint under stress. Finger box joints or tongue and groove joints may pull apart in two of the three possible x,y,z dimensions upon failure of the glue joint under stress. The weakest drawer box joint may be the lap joint or overlap joint and may pull apart in three of the possible x,y,z dimensions upon failure of the glue joint under stress.

It would therefore be advantageous to create or manufacture a drawer box joint that was not susceptible to stress or failure in any of the three possible x,y,z dimensions over time, and create a joint that dramatically increases the glued joint surface area and did not require expensive mechanical plates for additional support.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages and limitations of previous solutions by providing a system and method for designing and manufacturing drawer box joints with improved strength and reliability under mechanical stress over time by dramatically increasing the glued surface area of the overlapping pieces of the drawer box joint, and fastening the pieces through multiple steps that prevent the movement of the joint in any of the three x,y,z dimensions in the event of a glue joint failure without the use of additional expensive mechanical plates.

One embodiment of the present invention may include a finger box joint, a round hole drilled through the top corner of the joint, a dowel peg placed into the hole in the interlocking fingers, a set of finishing nails driven into one or more sides of the interlocking fingers in the corner joint such that the finishing nails are driven into and through the dowel peg and into the opposing corner piece.

Another embodiment of the present invention may include a dove tail joint, a square or rectangular hole drilled through the top corner of the joint, a square or rectangular peg placed into the hole in the interlocking fingers, one or more screws turned into one or more sides of the interlocking fingers in the corner joint such that the screws are turned into and through the square or rectangular peg and into the opposing corner piece.

The advantages of the present invention are that it has an increased gluing surface area resulting in a much higher strength joint and results in a joint that will not fail in any one dimension of the x,y,z plane. Additional metal plates are not needed to achieve the final joint strength. In some cases the resulting joint will not have to be clamped during the cure time of the glue due to its construction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of prior art for a box finger joint.

FIG. 2 is an illustration of an embodiment of a finger box joint which utilizes a dowel peg and finishing nails.

FIG. 3 is an illustration of an embodiment of a left side cross section of a finger box joint in FIG. 2 which utilizes a dowel peg and finishing nails.

FIG. 4 is an illustration of an embodiment of a right side cross section of a finger box joint in FIG. 2 which utilizes a dowel peg and finishing nails.

FIG. 5 is an illustration of an alternative embodiment of a finger box joint which utilizes a square or rectangular peg and finishing nails on both sides of the joint.

FIG. 6 is an illustration of an alternative embodiment of a finger box joint which utilizes variable sized interlocking fingers, partial feed through dowel pegs and finishing nails on both sides of the joint.

FIG. 7 is an illustration of an embodiment of a left side cross section of a finger box joint in FIG. 6 which utilizes variable sized interlocking fingers, partial feed through dowel pegs and finishing nails on both sides of the joint.

FIG. 8 is an illustration of the various types of pegs that may be placed in the corner and through the interlocking fingers of the finger box joint.

FIG. 9 is an illustration of an alternative embodiment of a two piece “T” shaped interlocking corner joint which utilizes a dowel peg and finishing nails.

FIG. 10 is an illustration of an alternative embodiment of a three piece “T” shaped interlocking corner joint which utilizes a dowel peg and finishing nails.

DETAILED DESCRIPTION OF THE INVENTION

The specific embodiments of the invention are described in this section. The embodiments that follow below were selected to illustrate the various features of the invention, but should not be construed to limit the invention to the embodiments illustrated and described, as the invention is susceptible to various modifications and alternate forms. In general, the embodiments were selected to bring to light the inventive feature, aspects and components of the invention. The invention is intended to cover all variations, modifications and equivalents falling within the scope and nature of the invention as described by the claims.

The invention may be embodied as individual methods, containers, boxes, drawers or part of tables, cabinets, night stands, dressers or any type of furniture or fixture that contains a corner joint. The angle of the corner joint may be 90 degrees but is not limited to any angle including the range from 0 to 180 degrees or from 0 to −180 degrees. The corner joint may be composed of two or more interlocking pieces. In the case of two interlocking pieces, an “L” or a “T” shaped corner joint may be formed. In the case of three interlocking pieces, a “T”, “Y” or an “X” shaped corner joint may be formed. In the case of 4 interlocking pieces, an “X” shaped corner joint may be formed. The number of interlocking pieces and angle between each interlocking piece is not limited, nor is the number of geometric shapes that can be formed at the interlocking corner joint. The illustrations shown in the FIGS. 1 through 8 shows various embodiments of a two piece “L” shaped interlocking corner joint. FIG. 9 shows an alternative embodiment of a two piece “T” shaped interlocking corner joint. FIG. 10 shows an alternative embodiment of a three piece “T” shaped interlocking corner joint. Anyone skilled in the art may be able to extend the inventive concepts illustrated in FIGS. 1 through 10 to create the additional geometric shapes mentioned above or any additional geometric shape from any number of interlocking pieces. The invention may be comprised of stone, stone composite, metal, molded or formed metal, plastic, glass, wood, glue, epoxy resin, fiber glass, polymer resin, plexiglass or any formed, welded, shaped or cut material.

FIG. 1 illustrates prior art of a box finger joint 100. The left side 101 of the box finger joint 100 is created by cutting or forming the alternating left side interlocking fingers 104. In a similar manner, the right side 102 of the box finger joint 100 is created by cutting or forming the alternating right side interlocking fingers 103. Subsequently the left side 101 and right side 102 are joined together and the interface between the right side interlocking fingers 103 and left side interlocking fingers 104, are typically glued and clamped in a clamping device until dry.

FIG. 2 illustrates an embodiment 200 of the present invention showing stronger box finger joint with dowel peg and finishing nails. The left side 201 of the box finger joint 200 is created by cutting or forming the alternating left side interlocking fingers 204. In a similar manner, the right side 202 of the box finger joint 200 is created by cutting or forming the alternating right side interlocking fingers 203. Subsequently the left side 201 and right side 202 are joined together and the interface between the right side interlocking fingers 203 and left side interlocking fingers 204, and are typically clamped in a clamping device. While still in the clamping device, a round hole is drilled at the top corner of 200. The pieces can now be removed from the clamping device. Glue is placed in the drilled hole and at the interface of the right and left side interlocking fingers 203 and 204 respectively. The pieces are clamped in a clamping device and subsequently a dowel peg 206 is placed in the hole. After insertion of the dowel peg 206, finishing nails 205 are driven into the right side interlocking fingers 203 and through the dowel peg 206 and into the left side 201. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the box finger joint with dowel peg and finishing nails 200 is completed but prior to the glue cure time. The order in which the interlocking fingers 203 and 204, the hole for the dowel peg 206 are formed, as well as the order of the glue application and clamping may be varied.

FIG. 3 is an illustration of an embodiment 300 of a left side cross section of the corner of the box finger joint with dowel peg and finishing nails 200 in FIG. 2. The left side 301 is aligned so that the left side interlocking fingers 304 are perpendicular to the right side interlocking fingers 303. The hole is drilled at the corner of 300 through the left and right side interlocking fingers 304 and 303 respectively. The location of the dowel peg 306 inserted into the hole and through 303 and 304 is shown. The finishing nails 305 may be driven into the right side interlocking fingers 303 and through the dowel peg 306 and into the left side 301.

FIG. 4 is an illustration of an embodiment 400 of a right side cross section of the corner of the box finger joint with dowel peg and finishing nails 200 in FIG. 2. The right side 402 is aligned so that the right side interlocking fingers 403 are perpendicular to the left side interlocking fingers 404. The hole is drilled at the corner of 400 through the right and left side interlocking fingers 403 and 404 respectively. The location of the dowel peg 406 inserted into the hole and through 403 and 404 is shown. The finishing nails 405 may be driven into the right side interlocking fingers 403 and through the dowel peg 406 and into the left side.

FIG. 5 illustrates an alternative embodiment 500 of the present invention showing stronger box finger joint with square peg and finishing nails. The left side 501 of the box finger joint 500 is created by cutting or forming the alternating left side interlocking fingers 504. In a similar manner, the right side 502 of the box finger joint 500 is created by cutting or forming the alternating right side interlocking fingers 503. Subsequently the left side 501 and right side 502 are joined together and the interface between the right side interlocking fingers 503 and left side interlocking fingers 504, and are typically clamped in a clamping device. While still in the clamping device, a square or rectangular mortise hole is drilled at the top corner of 500. The pieces can now be removed from the clamping device. Glue is placed in the drilled or mortised hole and at the interface of the right and left side interlocking fingers 503 and 504 respectively. The pieces are clamped in a clamping device and subsequently a square or rectangular peg 506 is placed in the hole. After insertion of the square or rectangular peg 506, finishing nails 505 are driven into the right and left side interlocking fingers 503 and 504 respectively and through the square or rectangular peg 506 and into the left and right sides 501 and 502 respectively. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the box finger joint with square peg and finishing nails 505 is completed but prior to the glue cure time. The order in which the interlocking fingers 503 and 504, the hole for the square or rectangular peg 506 are formed, as well as the order of the glue application and clamping may be varied.

FIG. 6 illustrates an alternative embodiment 600 of the present invention showing stronger box finger joint with partial feed through dowel pegs and finishing nails. The left side 601 of the box finger joint 600 is created by cutting or forming the alternating left side interlocking fingers 604. In a similar manner, the right side 602 of the box finger joint 600 is created by cutting or forming the alternating variable sized right side interlocking fingers 603. Subsequently the left side 601 and right side 602 are joined together and the interface between the right side variable sized interlocking fingers 603 and left side interlocking fingers 604 is typically glued and clamped in a clamping device. While still in the clamping device, a hole is drilled at the top corner of 600. The hole at the top corner of 600 typically may not go all the way through 600 but may stop almost half way through 600. Glue is placed in the drilled top hole and subsequently a top side partial feed through dowel peg 606 is placed in the hole. In a similar manner, a hole is drilled at the bottom corner of 600. The hole at the bottom of the corner of 600 typically may not go all the way through 600 but may stop almost half way through 600. Glue is placed in the drilled bottom hole and subsequently a bottom side partial feed through dowel peg 607 is placed in the hole. After insertion of the top and bottom partial feed through pegs 606 and 607 respectively, finishing nails 605 are driven into the right and left side interlocking fingers 603 and 604 respectively and through the top partial feed through peg 606 and bottom partial feed through peg 607 and into the left and right sides 601 and 602 respectively. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the box finger joint with partial feed through dowel pegs 606 and 607 and finishing nails 605 is completed but prior to the glue cure time. The order in which the interlocking fingers 603 and 604, the holes for the partial feed through pegs 606 and 607 are formed, as well as the order of the glue application and clamping may be varied.

FIG. 7 is an illustration of an embodiment 700 of a left side cross section of the corner of the box finger joint with partial feed through dowel pegs and finishing nails 600 in FIG. 6. The left side 701 is aligned so that the left side interlocking fingers 704 are perpendicular to the variable sized right side interlocking fingers 703. The hole is drilled at the corner of 700 through the left and variable sized right side interlocking fingers 704 and 703 respectively. The location of the top side partial feed through dowel peg 706 and bottom side partial feed through dowel peg 707 inserted into the top and bottom side holes respectively and through the right side variable sized interlocking fingers 703 and left side interlocking fingers 704 is shown. The finishing nails 705 may be driven into the right side variable sized interlocking fingers 703 and left side interlocking fingers 704 and through the partial feed through dowel pegs 706 and 707 and into the left side 701 and into the opposing side piece.

Alternatively the round top side and bottom side partial feed through dowel pegs 706 and 707 respectively may be replaced by but is not limited to square pegs, rectangular pegs, epoxy resin, fastening nails, staples, screws or any other type of tapered or stepped shaped peg. The appropriate top and bottom sized holes need to be first drilled to fit the screw or geometric shape of the peg chosen. In addition, the finishing nails 705 may be omitted or replaced by but is not limited to screws or other type of hole and smaller peg. Also the finishing nails 705 may only go partially through the top side and bottom side partial feed through dowel pegs 706 and 707 respectively. The right side variable sized interlocking fingers 703 and left side interlocking fingers 704 may be replaced by but is not limited to dovetail joints or any other type of full or partial interlocking finger joint. A right side cross section of 600 in FIG. 6 is not shown but should be obvious to the reader based on the previous discussion of FIG. 2, FIG. 3 and FIG. 4.

FIG. 8 illustrates an embodiment 800 of the present invention showing various sized and shaped pegs that may be used in place of 706 and 707 in FIG. 7. The size and shape of the pegs may take the form but are not limited to the pegs 801, 802, 803 and 804 shown. 801 is an exemplary illustration of a round dowel peg. 802 is an alternative exemplary illustration of a square or rectangular peg. 803 is an alternative exemplary illustration of a variable step round peg. 804 is an alternative exemplary illustration of a tapered round peg.

FIG. 9 illustrates an alternative embodiment 900 of the present invention showing a stronger two piece “T” shaped box finger joint with dowel peg and finishing nails. The front side 901 of the box finger joint 900 is created by cutting or forming the alternating front side interlocking fingers 904. In a similar manner, the back side 902 of the box finger joint 900 is created by cutting or forming the alternating back side interlocking fingers 903. Subsequently the front side 901 and back side 902 are joined together and the interface between the back side interlocking fingers 903 and front side interlocking fingers 904, and are typically clamped in a clamping device. While still in the clamping device, a round hole is drilled at the top corner of 900. The pieces can now be removed from the clamping device. Glue is placed in the drilled hole and at the interface of the back and front side interlocking fingers 903 and 904 respectively. The pieces are clamped in a clamping device and subsequently a dowel peg 906 is placed in the hole. After insertion of the dowel peg 906, finishing nails 905 are driven into the front side interlocking fingers 904 and through the dowel peg 906 and into the back side 902. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the two piece “T” shaped box finger joint with dowel peg and finishing nails 900 is completed but prior to the glue cure time. The order in which the interlocking fingers 903 and 904, the hole for the dowel peg 906 are formed, as well as the order of the glue application and clamping may be varied.

Alternatively, the back side interlocking fingers 903 may only come partially through the front side 901. In addition, the front side interlocking fingers 904 may not be cut all the way through to the front side 901. This is what is known as a blind interlocking box finger joint since the back side interlocking fingers cannot be seen from the front face of the front side 901.

Other alternative embodiments may combine a tongue and groove joint with the interlocking finger box joint. A channel or dado is first cut through the back face of the front side 901 where it intersects with the back side 902. Subsequently the front side interlocking fingers 904 may then be formed in the front side 901. The back side interlocking fingers 903 may then be formed. The depth of the back side interlocking fingers 903 may be cut equal to the thickness of the front side 901 minus the depth of the channel or dado cut into the back face of the front side 901. The front side 901 and the back side 902 may then be combined with the back side 902 partially embedded into the dado or channel in the front side 901.

FIG. 10 illustrates an alternative embodiment 1000 of the present invention showing a stronger three piece “T” shaped box finger joint with dowel peg and finishing nails. The left side 1001 of the box finger joint 1000 is created by cutting or forming the alternating left side interlocking fingers 1004. The right side 1008 of the box finger joint 1000 is created by cutting or forming the alternating right side interlocking fingers 1007. In a similar manner, the back side 1002 of the box finger joint 1000 is created by cutting or forming the alternating back side interlocking fingers 1003. Subsequently the left side 1001, right side 1008 and back side 1002 are joined together and the interface between the back side interlocking fingers 1003, left side interlocking fingers 1004 and right side interlocking fingers 1007, are typically clamped in a clamping device. While still in the clamping device, a round hole is drilled at the top corner of 1000. The pieces can now be removed from the clamping device. Glue is placed in the drilled hole and at the interface of the left, right and back side interlocking fingers 1004, 1007, and 1003 respectively. The pieces are clamped in a clamping device and subsequently a dowel peg 1006 is placed in the hole. After insertion of the dowel peg 1006, finishing nails 1005 are driven into the left and right side interlocking fingers 1004 and 1007 and through the dowel peg 1006 and into the back side 1002. The clamping device may be left in place until the glue has cured. Alternatively the clamping device may be removed after the three piece “T” shaped box finger joint with dowel peg and finishing nails 1000 is completed but prior to the glue cure time. The order in which the interlocking fingers 1003, 1004 and 1007, the hole for the dowel peg 1006 are formed, as well as the order of the glue application and clamping may be varied. 

What is claimed is:
 1. A method comprising: a corner joint of with at least one interlocking finger from at least two separate pieces; at least one hole cut through the top or bottom corner of the joint and cut through at least one of the interlocking fingers from at least two pieces; at least one peg placed into each hole cut through the top or bottom corner of the joint with the peg extending through at least one of the interlocking fingers from at least two pieces; a glue or epoxy resin formed at the interface of the interlocking fingers, holes and pegs.
 2. The method of claim 1 wherein said corner joint is a box finger joint, a blind box finger joint, a dovetail joint, a blind dove tail joint, a tongue and groove joint, a lap joint; and the method of claim 1 wherein the said corner joint is any variable sized and shaped interlocking finger joint.
 3. The method of claim 1 wherein the said hole is a round hole, a square hole, a rectangular hole, any geometrically shaped hole; and the method of claim 1 wherein the said hole is any geometric shaped hole which may be tapered or stepped.
 4. The method of claim 1 wherein the said hole may be cut completely through the top and bottom of the said corner joint and said interlocking fingers; and the method of claim 1 wherein the said hole may be cut partially through the top or bottom of the said corner joint and at least one said interlocking finger from at least two said pieces.
 5. The method of claim 1 wherein a first said hole may be cut partially through the said corner joint from the top and through at least one said interlocking finger from at least two said pieces; and the method of claim 1 wherein a second said hole may be cut partially through from the bottom of the said corner joint and through at least one said interlocking finger from at least two said pieces.
 6. The method of claim 1 wherein the said peg is a screw, a nail, a staple, an epoxy resin that partially fills the said hole, an epoxy resin that fully fills the said hole, a round dowel peg that matches the diameter of the said hole, a rectangular peg that matches the dimensions of the perimeter of the said hole, is any geometrically shaped peg that matches the dimensions of the said hole; and the method of claim 1 wherein the said peg may be any geometrically shaped peg that may be tapered or stepped and that matches the dimensions of the said hole.
 7. The method of claim 1 where the said pieces with said interlocking fingers form an “L” shaped said corner joint, a “Y” shaped said corner joint, a “T shaped said corner joint, an “X” shaped said corner joint; and the method of claim 1 wherein the said pieces combine to form any multiple side, geometric shaped, said corner joint wherein the angle between any two adjacent said pieces of the said corner joint may vary from 0 to 180 degrees or from 0 to −180 degrees.
 8. The method of claim 1 wherein the order in which the said interlocking fingers are formed, at least one said hole for at least one said peg are formed, as well as the order of the said glue or said epoxy resin application at the interface of the said interlocking fingers, interface of at least one said hole, interface of at least one said peg and the clamping in a clamping device of the said corner joint may be varied.
 9. The method of claim 1 wherein at least one screw, nail, staple, at least one any geometrically cut hole and at least one matching shaped pin may be driven into at least one said interlocking finger and partially through or completely through at least one said peg and into at least one opposing side said piece at any angle from 0 to 180 degrees or from 0 to −180 degrees.
 10. The method of claim 1 wherein the said corner joint may be composed of but not limited to stone, stone composite, metal, molded or formed metal, plastic, glass, wood, glue, epoxy resin, fiber glass, polymer resin, plexiglass or any formed, welded, shaped, and cut material.
 11. A method comprising: a corner joint with at least one interlocking finger from at least two separate pieces; at least one hole cut through the top or bottom corner of the joint and cut through at least one interlocking finger from at least two pieces; at least one peg placed into each hole cut through the top or bottom corner of the joint with the peg extending through at least one interlocking finger from at least two pieces; at least one pin driven through at least one interlocking finger of the corner joint and partially through or completely through at least one peg and into at least one opposing side piece; a glue or epoxy resin formed at the interface of the interlocking fingers, holes, pegs and pins.
 12. The method of claim 11 wherein said corner joint is a box finger joint, a blind box finger joint, a dovetail joint, a blind dove tail joint, a tongue and groove joint, a lap joint; and the method of claim 11 wherein the said corner joint is any variable sized and shaped interlocking finger joint.
 13. The method of claim 11 wherein the said hole is a round hole, a square hole, a rectangular hole, any geometrically shaped hole; and the method of claim 11 wherein the said hole is any geometric shaped hole which may be tapered or stepped.
 14. The method of claim 11 wherein the said hole may be cut completely through the top and bottom of the said corner joint and said interlocking fingers; and the method of claim 11 wherein the said hole may be cut partially through the top or bottom of the said corner joint and at least one said interlocking finger from at least two said pieces.
 15. The method of claim 11 wherein a first said hole may be cut partially through the said corner joint from the top and through at least one said interlocking finger from at least two said pieces; and the method of claim 11 wherein a second said hole may be cut partially through from the bottom of the said corner joint and through at least one said interlocking finger from at least two said pieces.
 16. The method of claim 11 wherein the said peg is a screw, a nail, a staple, an epoxy resin that partially fills the said hole, an epoxy resin that fully fills the said hole, a round dowel peg that matches the diameter of the said hole, a rectangular peg that matches the dimensions of the perimeter of the said hole, is any geometrically shaped peg that matches the dimensions of the said hole; and the method of claim 11 wherein the said peg may be any geometrically shaped peg that may be tapered or stepped and that matches the dimensions of the said hole.
 17. The method of claim 11 wherein the said pin may be a screw, a nail, a staple, any geometrically shaped peg after the same shaped hole is cut through any individual said interlocking finger and partially through or completely through the said peg and into at least one opposing side said piece at any angle from 0 to 180 degrees or from 0 to −180 degrees.
 18. The method of claim 11 wherein the said pieces with said interlocking fingers form an “L” shaped said corner joint, a “Y” shaped said corner joint, a “T shaped said corner joint, an “X” shaped said corner joint; and the method of claim 11 wherein the said pieces combine to form any multiple side, geometric shaped, said corner joint wherein the angle between any two adjacent said pieces of the said corner joint may vary from 0 to 180 degrees or from 0 to −180 degrees.
 19. The method of claim 11 wherein the order in which the said interlocking fingers are formed, the order of at least one said hole for at least one said peg, at least one hole for at least one said pin, as well as the order of the said glue or said epoxy resin application at the interface of the said interlocking fingers, interface of at least one said hole, interface of at least one said peg and interface of at least one said pin and the clamping in a clamping device of the said corner joint may be varied.
 20. The method of claim 11 wherein the said corner joint may be composed of but not limited to stone, stone composite, metal, molded or formed metal, plastic, glass, wood, glue, epoxy resin, fiber glass, polymer resin, plexiglass or any formed, welded, shaped and cut material. 